Horticultural growing containers, such as flower pots, are commonly filled and seeded in mass quantities at nurseries during large scale plant propagation operations. At the beginning stages of propagation, the containers can be loaded into trays configured to hold and arrange multiple containers. The loaded trays can serve as an efficient means for organizing, filling and seeding the containers at the nursery, for transporting containers with grown plants to retail centers, and for ultimately displaying the plants to consumers. The trays can not only be utilized throughout the course of filling, planting, transportation and display of the containers, but can also, after being emptied of containers by retail consumers, be returned from the retail center to the nursery for re-use.